A little background to set the scene...
Phoenix Caged was originally intended as a survival-horror style game for 3rd edition D&D. Its original purpose was to present a fantasy version of many of the common urban horror tropes; a post-apocalyptic world of vampires, were-wolves, and zombies. Over time both the structure and nature of the setting evolved; first, the various races and entities populating the world, and then the rule-set used to present it to its audience.
Today, Phoenix Caged maintains the original premise and embraces those old tropes, but it presented as a conceptual setting that can be slotted into whatever system you happen to be playing. Its plug-and-play nature allows it be adjusted for any fantasy-focused TTRPG system in existence, from the common D&D rules, to the more exotic Cypher System. My intention is to provide enough background information on the setting, and some very general suggestions for various game systems so that you can customize it to your preferred rule-set. Phoenix Caged is supposed to be specifically generic enough that it can work with just about any style of game/system/play style there is, while allowing for you to grow your game and make the setting uniquely yours.
The Basic Premise
Phoenix Caged can run the gamut from its original survival-horror roots, to a general high adventure game. Political dynasties can be built up or rent asunder. An epic quest to free Phoenix from her cage could be under-taken. Perhaps the legendary Dragon theru might resurface as a threat or boon to the world. This is a game that encourages the strange; where monsters can be heroes and the only light in a fast approaching darkness.
'Vampires' exist as the Daiharu, divorced into the noble and sometimes arrogant Radiant, or the shadowy and mysterious Umbral. Why would the vampires side with the humans and protect them from the undead? Simply, because they need food. And it is fundamentally easier to raise sheep than to go hunting. You're also less likely to endanger your food supply with extinction. What, for the daiharu, was originally a practical decision for their own survival, defined their cultural identities as the saviours and predators of humanity.
Were-wolves (and other shapeshifters) are a common trope in urban fantasy, movies, tv shows and the like. Current modern story-telling frequently wants to make such creatures heroic or misunderstood. So, I ran with that idea and came up with the tribes of Theru; the name derived from Greek word theriomorph (literally beast-shape, or 'possessing or depicted in the form of a beast').
Zombies, and other undead, are a consistent threat in this world. They serve as the post-apocalyptic 'mutant', the dreaded zombie plague, and as a fundamental reason the daiharu, theru, and demon races protect and interact with humanity. Zombies exist for the sole purpose of wiping out humanity through absorption, corruption, and the destruction of identity. They are intended as both the very simple goblin/ kobold initial threat, and the worst conceivable threats well into the player's later careers.
So have fun! Add, modify, or subtract tribes. Use your favorite TTRPG. Tell an epic tale, or run a simple monty-haul one-shot.